A great look at how Mullard Thermionic valves (vacuum tubes) are made. Looks like this was made in the 1950's and shows some great footage of tubes/valves being made.
Apart from the valves, look at the vast number of highly precise machines that had to be made by very skilled machinists in the days before computers and CNC machines, simply incredible what can be achieved by hand and eye skills. I still have a 4-valve mains frequency oscillator I built to drive a big astronomical telescope that I also built back in the early 1960's. I used it to vary the speed of the 240 Volt synchronous induction drive motor. ( Handy for speeding up a time clock locked bank money vault!!)
Old automotive assembly line videos are also interesting to watch. There was so much manual labor involved in early cars. Almost every part was made in the same factory and from scratch.
My maternal grandfather was a German trained Master Machinist who worked as a Tool and Die maker for a large radio firm back from 20's to 40's. Later on he worked at a packaging company that needed machines to run the assembly line to build the packaging boxes, count the product, insert it into the box, seal it, etc. The things he could fabricate and machine were incredible. He could fabricate parts to fix my broken childhood toys. Simple parts for the car, etc. All without CNC and other modern technologies. They truly were craftsmen. When I look at this video, the one thing I do notice is the amount of people required to do simple tasks (measuring and weighing the glass tubing for example) that can now be done automatically freeing up the technician to work on more complex tasks.
A friend of my mothers worked at this factory. Imagine my surprise as a young electronics know-it-all to be given a comprehensive lesson on how valves worked, by someone I looked on as an auntie!
The constantly growing amazement with vintage tube technology is incredible. I do not think it will ever go away....there is just a fascination of watching the tubes fire up and waiting patiently to hear that white noise and static and finally the gratification of tuning in a station. Even more fascinating is still tuning in a station on shortwave from across the planet using a radio from the 1930's....it just....is!
So true, I grew up with valve radio, there's almost a magic to them if it's the voltage regulator valve on the RCA AR88, of those wonderful green tuning valves
@@freesaxon6835 I was born in 1977 and so vacuum tubes/valves were long gone by the time I came along. But when I was a little kid in the early 1980's, for some weird reason there was an old radio in the apartment where we lived that had vacuum tubes. It actually worked, and I remember sometimes I would turn it on and I was fascinated with seeing the tubes glow. I loved looking through the back of the radio and seeing the glow and feeling the warmth of the tubes. There was even a distinct smell which now I know all old radios seem to have. It left such an impression on me that I was fascinated with vacuum tubes ever since. Years later, I started collecting antique radios and I learned how to fix them. Recently, I've even restored a couple of antique tvs. There really is something amazing about it. Out of all my hobbies, working with antique vacuum tube electronics is one of the most fun and rewarding. I think I was extremely lucky to have that experience as a kid...I seriously doubt that many people my age had that chance! My first time seeing an old vacuum tube radio was one that was actually working, "in the wild" and not in an antique shop! In the 1980's!
It is also worth noting that the video is, in fact, a film, recorded using optics and chemistry, with a sound-track which was almost certainly recorded for playback, on the film strip, for pickup and playback by a photo-sensitive valve.
All this, from design to manufacture and even automation, without even the benefit of a pocket calculator. It reminds me how central science and technology were to education and how skills like mental arithmetic were prized.
The vacuum tube truly is a magic lantern. It brought people together, made communication easier and changed the way we used electricity for sound & pictures to transmit, store and shape it. The warm glow of every vacuum tube is the visible human touch and a constant reminder that big changes have seemingly small beginnings.
@@WinrichNaujoks Analytical chemist - incoming raw materials, alloy composition, plating baths etc. At Simonstone (which made CRT tubes - remember those?!) there was also environmental monitoring - air quality in the working environment, gas discharge to the atmosphere, water to the drainage system etc.
I used to service valve TVs fitted with the EF80, then commonly used in intermediate frequency amplifiers and which was highly reliable. This valve, and others, was later replaced by the frame grid version made to a higher degree of precision, the EF184. having a greater gm. In 1965 I visited the vast Blackburn valve factory in Lancashire England and was very impressed by the manufacturing processes involved. There was a guy for example who fitted top caps to power valve anodes and who could tell he was using the correct amount of cement by weighing his supply. The film did not dwell too much on the fact that newly-made valves do not function immediately, but need to be aged for about 24 hours before they reach the full emission, specified for the particular Mullard valve type tested. There was a room full of glowing valves receiving this treatment. Those that did not reach the standard required were not necessarily discarded as many were packaged under various other trade names and sold more cheaply than the Mullard branded ones. Many professional performers today seem to prefer the sound of audio valve amplifiers over those of solid state ones. The first transistor amplifiers suffered from defects such a cross-over distortion at low sound levels but this is no longer a problem. Valve amplifiers are electrically much more robust than solid state ones and so can withstand the misuse and overloading which might destroy transistor ones. In addition the type of distortion produced by a valve amplifier does not really sound as unpleasant as a transistor one, and in fact many performers turn up their gains to maximum in order to produce this type of sound.
@@pomme4682 The ageing used the 'getter', a sort of odd ring on the top of the upper mica sheet, used to capture gaseous impurities and ensure, as close as could be achieved, a perfect vacuum.
Valves are still wonderful devices. They give wonderful sound to stereo. They are in some of my test equipment among other things and still provide good and useful service. This video shows the great care taken to make the fine valves that I enjoy even today with some of them built as far back as the 40's and considerably predating me!
And where is it now? The "modern" world, in general, has moved away from manufacturing, leaving this task to developing countries. What do we, especially in North America, make ? Very little. No longer builders and makers, we are now just profligate consumers relying on others to make our "stuff".
I just got a tube amplifier for my hifi system and wow there is just something about it that cannot be matched by modern solid state transistor amplifiers. I love this technology.
I am still use a British made tube intergrated amplifier. It sounds sweet on vocal and modern amp unable to provide. It is my source of joy playing the tube amp. Only problem is hard and expensive to get vintage replacement tubes.
@@PeterWalkerHP16c Mosfet power transistors are close to the valves about sound quality.... But just close. Audio watts provided by valves are more "present" than semiconductors watts !! I own an home made stereo valves amplifier, powered with ECL82 valves, sounds louder than a 2x10 watts transistor amp. Well used an ecl82 valve gives 4 watts rms (single), paired in a push pull, you have 8w rms output !
@@cletusspuckler2243 Easily done. I've built filters that add or remove harmonics and the difference between the valve and solid state is inaudible like -40dB. They switched in with a 'Valve' switch.
Enjoyable video to watch. I especially liked the rubber hammer where the inspector was making sure the valve (tube) did not ring because of vibration inducing harmonics.
@@stephensaines7100 The sad part is that this still exists today in big parts of the world, third world countries and many prisons. Not to talk about the conditions these people are in. Production technologie is remarkable and sad at the same time.
I just got an Emerson 811 tabletop radio set from1955 a couple of years ago and it is as old as I am. I recall using valve sets back in the early 70s and I have the curiosity of looking at that technology back then, once more, that I find amazing. Thanks for the videos and the opportunity to know the past, to understand the present and be ready for the discovery of the next big thing in electronics.
I have a 1954 Australian made Hotpoint radio with original valves. Still works. It's amazing when the first electronic Computers were built using valves. One valve was equivalent to one transistor in the first transistor Computers. Now billions of transistors can fit on a tiny piece of silicon no bigger than a finger nail.
On one hand, I’m enjoying watching this video on my IPad with all its nano-scale circuitry. On the other hand, I lament the fact that all the people who had steady employment in factories like this no longer have jobs. I know assembly line work is hard, boring, long hours for low pay, but it’s better than no job and no pay because the company makes more profit buying cheaper parts from high automation low cost factories in China.
Not to mention all the skilled machinists and tool & die makers that made and maintained the automated factory machines that made the tubes. We allowed NAFTA and China to export all that skill and craftsmanship out of the US leaving countless factories empty and towns blighted.
I use and maintain valve equipment everyday for audio. Much of the equipment is as old or older than I and it still can't be equalled by semiconductors for audio production. The new valves being made today do not match the quality or longevity of vintage but at least valves are still being manufactured. LONG LIVE THE VALVE!
William Copeland, I was thinking the same thing about the performance and reliability of vintage electronics. When you look at how much quality control went into each stage of manufacturing it shows they were made to a specification, not a price. Nowadays when you have factories in China pumping out millions of semiconductors every day for a few cents each, they can’t possibly have the same quality, nor do they care. Higher quality would mean lower profits.
There's a reason a pair of the earliest Marantz or other top shelf preamps in excellent shape can set you back $5,000 or more, and it isn't simply nostalgia.It's the sound, especially the REALISM, which doesn't show up on any lab testing results. Get yourselves some early, not-over-engineered tube components, spend a thousand bucks having them rebuilt by an old-school tube-gear tech, without changing the simplicity, and a top shelf used, belt-drive turntable with a strong motor and heavy platter (and get it set up by somebody who knows what they are doing), and some big, heavy, efficient, well made vintage speakers that suit your music and ears and rediscover the joys of analog vinyl (be sure to clean them well after buying them) played through those magical little glass thingies. It's worth it.
It is amazing just how much some of these original vacuum tubes from Mullard are worth today!! Many of the tubes used in preamplifier stages can cost upward of $300.00 to $400.00 each. I have some NOS (New Old Stock) Telefunken 12AX7 tubes in a VTL preamplifier that are very rare nowadays and are worth $500.00 to $600.00 each! I have no intention of selling them because nothing else comes even close to their quality of sound. Most of the tubed guitar amps used by musicians have tubes manufactured in Russia or China. Their quality control is just average to poor. The finest vacuum tubes ever made were from England, Germany, and America.
Try the cheap brimar 6060,= 12at7. They beat the teles flat. Even if you plug into a socket meant for tele 12ax7. Especially the 3mica ring getter version.
A lot of information from the type number: EF80: E=Filament voltage 6.3V; F=Penthode; 8=9 pin socket. Low noise, HF pre amplifier tube. The same tube but then for 300mA filament current was the UF80. I can't imagine that nowadays such a documentary would be produced about the assembly of smartphones, let alaone that anyone would be interested.
..Yeh, they are great..I collect them myself..its a very interesting hobby..as there are just so many different ones...of all shapes & sizes....& their numbering sequences can be very interesting as well...as for ex..you get one type..where there can be god knows how many different versions..each version carrying a different number..although technically being the same valve..more often than not each individual version will look different.to the other ones...there are Common ones, also there are some very Rare & collectable ones too..of which I have forked out sometimes Hundreds of G.B.P...on Ebay site to aquire them for my collection...!!! :)
Women's work always paid a lot less in the UK at that period, and nothing has changed very much. I would be very interested to know whether it is "equal pay for equal work" in China now.
Tube testers don't need to contain tubes, although some do have valve rectifiers. Tubes can be tested with battery power, which removes the need for rectification.
My question the different vacuum tubes, ie black plates, square getters or gold getters although they are all by the same manufacturer do they sound different and why?
Shape of the grids and anodes, materials, deepenes of vacuum, there are TONS of different variables in a vacuum tube compared to a transistor which really has different qualities depending on the ESD it got esposed to
+Sniper5354 Valve/Tube manufacture was the bleeding edge technology of it's day, and drove the development of high purity / high temperature metals, exotic alloys, and other areas of materials science. Much as semiconductor manufacture does today. I am amazed by just how much of the work was done by hand, with or without jigs. I do believe that toward the end of tube manufacture, the "mounts" for high volume types were automatically assembled.
+Bob Weiss Agreed, those valves were used in military equipment, hence they spared no expense on resources. I wonder if those workers were poisoned by the chemicals which may be toxic or radioactive. I am an audiophile. Looking at the production of these tubes, all other audio gears/components seem like toys. How much do audio grade capacitors and cables cost?
@@stephanesonneville Indeed. The same applies to cables. Even the most ordinary installation wire is 99.9999¨% 'pure' copper and completely 'oxygen free'. Only a complete idiot will pay hundreds of dollars for a speaker cable.
400th "like". I keep getting sucked in by vacuum tubes, but there's already too much on my plate because I live in a gridded environment. [Oh, stop complaining. I know you wish You'd said that first.]
+orange70383 In short, the unusual heater construction. They used a coiled insulated heater, with ends that were bare wire to make the connections to. The bare ends heat much faster than the coated part, causing a flash.
yes and the part inside the cathode is still cold which makes for a low resistance which causes the bare part to get more voltage than it should for a short while.
@@alexstevensen4292 , some tubes were designed with special fast-heating filaments or heaters, primarily for use in series-string radios so that all the tubes heated quickly and no one particular tube got hit with excessive filament voltage or current at turn-on. Not sure if this applied to 12AX7s and the like, but those DID show up in series-string sets.
orange70383 You could argue that this is simply 'heater flash'. A phenomenom where (like others have pointed out in this comment section) the heater wire becomes whitehot at some parts due to uneven current consumption allong the lenght of the total heater wire. Altho this might be considered 'normal' for Mullard tubes and other brands like Telefunken, heater flash does eventually shorten the life of your vacuumtube. Sometimes even drammatically shortening the lifespan of the tube. Because remember; when the fillament (heater wire in a indirectly heated vacuumtube) burns up and goes open circuit, there is absolutley no electron emmision anymore, and thus renders the tube useless :'( Paul Carlson from 'Mr Carlsons lab' made a great video describing this issue with vacuumtubes as well as giving an excellent solution to the problem: Include a current limiting element (resistor, small lightbulb, etc.) in series with the heater connection to your tubes and also a simple switch which bridges that element when the switch is closed. Then you start up your tube with the switch opened, forcing the currentspike to be limited by that newly included element - preventing the heater wire to 'flash'. After maybe 10 seconds the entire heater wire would have heated up, might be a bit slower than normally doing this but who cares, and THEN you close the switch. Now the full whack of current can run trough the heater wire, here comes the clever part: Because of when you heat thungsten up its resistance goes up, the pre heated heater wire now WILL NOT flash like it did without the above method. Simple and very effective, it will definately improve the lifetime of your tubes, give it a try :D Here's the video where Paul explains: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-bX0o3jAzSBs.html
@@goodun6081 Got to disagree on that, you have it backwards. The 'A' added to a tube's model number (12AX7A, 50C5A, etc usually, though not always), indicates 'controlled warm-up characteristics' which *slowed* 'cold turn-on inrush'. I just checked, there are a number of explanations of this on-line.
We needed to wait until 1974 for H&S legislation which gave the goal of improving safety, rather than complying with laws, leading to PPE as we understand it today. 1937 was the first 'all workers' act. The original factories act was in 1801, and essentially designed to stop the abuse of children in factories.
@@westelaudio943 Yeaahhh...there's been a lot of hysteria about the (gist) 'Toxicity of manufacturing vacuum tubes and all the attendant pollutants and poisons'. True...however, solid state manufacturing is even more so!
I wondered on that too, not only for the oxidation by body oils and chemistry on the metal surfaces, but also the other way around, absorption of exotic chemicals.
This comes from a story that I believe was on the vintage radio forums. There was supposedly once an issue where women making valves had previously been fruit picking if I remember correctly, this caused problems with a batch of valves as the acids? in the fruit were still on their hands contaminating the glass, this caused premature failures in service and I believe free replacements were offered. @@stephensaines7100
@@dglcomputers1498 That is a myth. That glass is inpenetrable to everything including fruit juices. At worst case you get a fingerprint on the outside. Which is unwanted bot does not affect function.
Awesome , when mens works without computer , with only his brain ... Many small hands of women , works for everybody ... I have know thermoelectronic tube when i was tv repair ..next germanium diode and transistor , integrated ic ... Like this era ... F5IQX .....
It put food on the table and a roof over their heads. Can't say that much about today's part-time McJobs that so many nowadays need two and three of (that is, two and three part-time jobs for one person) to make ends meet. But, yes, I agree it must have been a repetittious and mind-numbing job.
@@patrickdemets6018 Here's a quick funny story though - I remember when Webster's dictionary said they were going to officially add "McJob" and McDonald's issued a statement saying "We are not amused." Yup, that was it! I thought that was hilarious!
There were/still are ways of controlling that externally, not least the use of a "Globar" ( negative co-efficient resistor) in series that reduced resistance as it warmed up. Beyond that, various 'soft turn-on' circuits have been derived over the decades, one of the simplest being to put a 'sacrificial' pilot light in series with the heater string. Solid state 'clamps' have been used for at least a couple of decades, very simple circuits with indefinite life spans.
Thermionic it is not correct name because there are not ions but electrons charge carrier for current into the bulb. The correct name is thermoelectronic effect.
